CBO DAC cable QSFP28 to 4×SFP28 passive, 3 m

The CBO DAC cable QSFP28 to 4×SFP28 passive, 3 m is a direct-attach copper assembly designed for short-reach, high-speed interconnects in data centers and network racks. With a single QSFP28 plug on one end and four SFP28 plugs on the other, this 3‑metre passive cable converts a 100G QSFP28 port into four separate 25G SFP28 links. It provides a low-latency, low-power alternative to optical transceivers for server-to-switch or switch-to-switch connections and is suitable for top-of-rack and aggregation deployments where cable simplicity and cost-efficiency are priorities.

Advantages

This passive DAC cable reduces power consumption and latency compared with active optical modules, while offering reliable electrical interconnection for short distances. The integrated QSFP28 to 4×SFP28 pinout allows straightforward aggregation of four 25G lanes without additional breakout modules. The fixed 3 m length helps maintain predictable signal performance and physical cable management in dense rack environments.

Suitable for

• 100G QSFP28 to 4×25G SFP28 breakout connections
• Server-to-switch and switch-to-switch short-reach links within the same rack or adjacent racks
• Top-of-rack aggregation and leaf-spine network segments
• Environments where reduced power consumption and low latency are required

Key specifications

• Connector types: QSFP28 on one end, four SFP28 on the other
• Type: Passive direct-attach copper (DAC)
• Supported data rate: 100G aggregated (4×25G lanes)
• Length: 3 metres
• Cable medium: Twinax copper
• Typical use: Short-reach interconnects in rack environments

How to use

Insert the QSFP28 connector into the 100G QSFP28 port of your switch or host, and plug each SFP28 connector into the corresponding 25G SFP28 ports on the remote device. Ensure that the network interfaces and transceiver settings on both ends are configured for 25G lanes or 100G breakout operation as required by your equipment. Route the cable to avoid sharp bends and secure it within the rack to maintain proper airflow and prevent strain on connectors.

Usage recommendations

Verify compatibility with your switch or server vendor’s supported cable list before deployment. Use the 3 m passive DAC for connections within the same rack or between adjacent racks; for longer links, consider active copper or optical solutions. Handle connectors by the housing and avoid touching contact surfaces to preserve signal integrity.